{ "id": "1711.07152", "version": "v1", "published": "2017-11-20T05:30:15.000Z", "updated": "2017-11-20T05:30:15.000Z", "title": "On $e$-positivity and $e$-unimodality of chromatic quasisymmetric functions", "authors": [ "Soojin Cho", "JiSun Huh" ], "comment": "22pages, 6 figures", "categories": [ "math.CO" ], "abstract": "The $e$-positivity conjecture and the $e$-unimodality conjecture of chromatic quasisymmetric functions are proved for some classes of natural unit interval orders. Recently, J. Shareshian and M. Wachs introduced chromatic quasisymmetric functions as a refinement of Stanley's chromatic symmetric functions and conjectured the $e$-positivity and the $e$-unimodality of these functions. The $e$-positivity of chromatic quasisymmetric functions implies the $e$-positivity of corresponding chromatic symmetric functions, and our work resolves Stanley's conjecture on chromatic symmetric functions of $(3+1)$-free posets for two classes of natural unit interval orders.", "revisions": [ { "version": "v1", "updated": "2017-11-20T05:30:15.000Z" } ], "analyses": { "subjects": [ "05E05", "05C15", "05C25" ], "keywords": [ "positivity", "natural unit interval orders", "unimodality", "chromatic quasisymmetric functions implies", "work resolves stanleys conjecture" ], "note": { "typesetting": "TeX", "pages": 22, "language": "en", "license": "arXiv", "status": "editable" } } }